Twitter has launched a "political index" which measures sentiment toward Barack Obama and Mitt Romney and reports it on a daily basis.
Buzzfeed has the details:
Twitter is launching a tool today that it says will fill that gap, and sort through the 400 million tweets a day from 140 million active users. Twitter and real-time search engine Topsy are launching the "Twitter Political Index," a daily assessment of how Twitter feels about Obama and Romney, in an election cycle that's being played out moment-to-moment on the social service.
The index, which Twitter has retained Democratic and Republican polling firms (the Mellman Group and North Star Opinion Research) to help perfect, appears to be the most serious and large-scale effort yet at a metric that has so far produced a lot of flops.
The rough version of how it works: Topsy pores through every single tweet in real time, determines which ones are about Obama or Romney, and then assigns a sentiment score to each tweet based on its content. That is, whether it's positive or negative toward Obama or Romney, and just how positive or negative it is. Add all the data up together and you have something like a real-time approval score for Obama and Romney, determined by what tens of millions of people are saying, which Twitter is going to release daily at election.twitter.com.